Embodiments of the present disclosure generally relate to blood glucose and more particularly to methods and devices that utilize electromagnetic principles to detect changes in the transmembrane electrolyte balance due to glucose induced fluid shift.
Congestive heart failure (CHF) is emerging as a major public health concern, representing a significant cause of hospitalization for individuals aged 65 years and older. Two of the most prominent risk factors for heart failure are hypertension (high blood pressure) and diabetes. Not only do people with diabetes tend to have a cluster of risk factors for heart diseases, including hypertension, obesity, insulin resistance, and abnormal blood lipid levels, but diabetes itself is also an independent risk factor for the condition. People with diabetes are more likely to develop heart disease than the general population.
For people with diabetes, there is growing evidence that controlling blood glucose levels is very important in preventing heart disease. According to the American Diabetes Association, self-monitoring of blood glucose (SMBG) has a positive impact on the outcome of therapy and helps to achieve specific glycemic goals. However, the inconvenience, expense, pain, and complexity involved in invasive measurement methods commercially available lead to underutilization, mainly in people with type II diabetes.
Today, certain noninvasive (NI) methods have been proposed for determining blood glucose levels. The convention NI methods fall into two categories. The first category of methods is based on the measurement of glucose using one or more of the intrinsic molecular properties of glucose, such as the near-infrared or mid-infrared absorption coefficient, optical rotation, Raman shifts, and photo-acoustic absorption, as well as others. The second category of methods measures the effects of glucose on the physical properties of blood and tissue. The second category of methods is based on an assumption that glucose is a dominant (highly fluctuating) blood analyte and, as such, contributes significantly to the change in the relevant physical parameters of the tissue. Hence, measurement of such parameters can lead indirectly to evaluation of the blood glucose (BG) level. The measured parameters are evaluated relatively to calibration, performed through correlation of the NI signal to a reference BG value. Therefore, the relative change of glucose in blood or interstitial fluid (ISF) plays the major role, as other blood analytes, which are less fluctuating, are fully or at least partially eliminated through calibration.
However, conventional methods for measuring blood glucose experience certain limitations. For example, non-invasive methods may require a blood sample to be taken before testing and/or may be available only when the patient visits a doctor's office. For example, at least some conventional methods use external devices that have sensors attached to the skin. The skin sensors present the potential for variations in the sensor-skin interface, changes in microcirculation, and metabolic rate etc. Those variables cause some challenges in measurement accuracy and sophisticated calibration is required for achieving required accuracy. Further, conventional methods may require the patient to take certain actions to perform the test at various times throughout the day.
A need remains for a blood glucose monitoring device and method that are accurate, painless, and easy-to-operate in order to encourage more frequent testing, leading to tighter glucose control and a delaying/decreasing of long-term complications and the associated health care costs.